Absa
Refusal to cancel debit order on my own account

I had good service at the branch. Customer service phoned to cancel a debit order. The answer was that in this case, I need written proof that I cancelled the debit order with Multichoice

What if I battle with Multichoice for 6 months to get any response? Is it not my right to ask my bank to cancel something I do not want to pay?

There I stand with a person willing to assist, with my valid ID, yet the bank is unhelpful to stop a debit order which I as their customer wants to cancel. How must I trust that they have my best interest at hand? Should they not, protect me instead of wanting something in writing from an useless company??